Synthetic materials have come into increasingly common use for the manufacture of furniture and carpeting for the home and equipment for use in a factory environment. Unfortunately, these synthetic materials often give off noxious gases when they burn. It is becoming quite common for fire departments to employ breathing apparatus for general use in fighting smoky fires. Such breathing apparatus includes a face mask, including a transparent viewing shield held in a frame which has a seal for preventing the gases from reaching the nose and mouth of the user. The breathing apparatus also includes an air tank and a hose interconnecting the air tank with the mask. When a firefighter is in a smoky environment, where vision is often so poor that a tag line is needed for the firefighter to retrace his steps to the exit, a firefighter can become disoriented quickly. It is desirable for him to have the ability to communicate to others in the area instructions as to fighting the fire or a need for help.
The equipment the firefighter wears when in a hot, smoky environment covers virtually all his skin area. His coat includes a collar for covering the neck and a strip is provided across the throat to protect that from burning, due to the intense heat. Such fully protective clothing makes it difficult to use transmitters which might be positioned to pick up vibrations due to talking from, for example, the esophagus or a facial bone. It was also undesirable to position a microphone inside the mask because wires had to either penetrate the shield or interrupt the seal. In any case, the running of the wires resulted in an opening for the entrance of the smoke or gases to the respiratory system of the firefighter. Additionally, the running and connection of wires from the face mask represents another step in the dressing of the firefighter in his protective clothing which takes extra time before he is ready. These loose wires can become caught and disconnected when the firefighter is moving quickly about in the low visibility environment, resulting in the loss of the ability to communicate. The manufacturers of the face mask equipment are responsible for its integrity and they do not want wires or other penetrations of their mask which might be a source of failure of their system.
A radio communication system has been proposed for use by emergency vehicle operators such as motorcycle highway patrol officers. This system includes a low power helmet mounted transmitter which communicates with a receiver mounted on the motorcycle. The receiver is connected to a higher power transmitter which can communicate with other receivers. The overall range of the communication is much greater than would be possible with the transmitter alone, and the system can include a voice actuated switch so that the motorcycle operator would not have to take a hand from the handlebar to operate the system. For further information regarding the structure and operation of this system, reference may be made to U.S. Pat. No. 3,908,168.